1. Field of Art
The present disclosure relates generally to an apparatus for expanding tubular members. More particularly, the present disclosure relates to an expansion cone having a geometry optimized for radial expansion of the tubular members.
2. Description of the Related Art
In the oil and gas industry, expandable tubing is often used for casing, liners and the like. To create a casing, for example, a tubular member is installed in a wellbore and subsequently expanded by displacing an expansion cone through the tubular member. The expansion cone may be pushed or pulled using mechanical means, such as by a support tubular coupled thereto, or driven by hydraulic pressure. As the expansion cone is displaced axially within the tubular member, the expansion cone imparts radial force to the inner surface of the tubular member. In response to the radial load, the tubular member deforms, increasing both its inner and outer diameters. In other words, the tubular member expands radially.
Expanding a tubular member in this manner can be problematic. After expansion, there will be significantly high residual strain in the tubular. In some applications, a casing is formed of a series of tubular members, such as pipe joints, threaded end-to-end and subsequently expanded, as described above. After expansion, there may be significantly high residual stress and strain in one or more of the threaded connections. The higher the residual stress and strain in a threaded connection, the greater the potential for the threaded connection to fail under load.
Accordingly, there is a need for apparatus that minimizes residual stress and strain levels in the expanded tubular.